Assigning property values question (possible Amay bug)

Hi,

The following html and css code:
    <p class="blue red">Hello</p>
    <p class="red blue">Hello</p>
    p.blue { color: blue; }
    p.red  { color: red; }
is not displayed in Amaya as in Mozilla or Internet Explorer.
Amaya displaies the first paragraph in red and the second one in blue.
Mozilla and IE display both paragraphs in red.

If the css rules order is changed:
     p.red  { color: red; }
     p.blue { color: blue; }
Amaya does not change colors, but Mozilla and IE display both 
paragraphs in blue.

Which order is most important? Class names order in html attribute or
class rules order in css file?

Best regards,
Barto